On Ubuntu 18.04, using the Unity desktop, when you hit the Super key it displays the Unity launcher menu from the top left of the screen, allowing you to browse your recently used files to quickly open them, or to search for any file on your system. In this menu, images for example, are previewed and that's a great feature.
But in the context of the current remote video calls trend due to the pandemic, when sharing your screen, you may need to start some app by using the Super key.
So, for privacy reasons, how can a single one of these file preview be simply removed in the Unity launcher menu, especially in the case of an image or a system file, as if they were never recently opened?
It will be difficult to remove a single thumbnail, because these are populated automatically according to certain algorithms. On the other hand, sharing your entire screen does exactly that: sharing your entire screen.
There are some workarounds:
sudo apt install rofi), dmenu (sudo apt install dmenu) or other launchers for the purpose.rofi, when run like
rofi -modi drun -show drunwill show you a text only, very quickly searchable menu of all your applications. You can bind that command to a hotkey to quickly pull it up anytime. It only consumes resources after you actually called it, and fully quits when you made your selection. Although you may not prefer in this context, you can have it show icons by adding-show-iconsto the command.